automated pre- and post- upgrade snapshots?

Thank you for creating and maintaining btrbk. Do you know if any pacman hooks exist for btrbk that could replace [snap-pac](https://www.archlinux.org/packages/community/any/snap-pac/) (for those of us switching from snapper to btrbk)? If they don't exist, I volunteer to help someone create & test them.

snap-pac makes pacman automatically use snapper to create [Snapper - ArchWiki](https://wiki.archlinux.org/index.php/Snapper#Pre/post_snapshots) like openSUSE's YaST. It uses [Pacman#Hooks](https://wiki.archlinux.org/index.php/Pacman#Hooks).

I assume somebody has already created such hooks for btrbk. If they don't exist, does anyone want to collaborate?

Start by reading the Pacman Hooks documentation and the snap-pac implementation linked in the issue, then compare how btrbk creates snapshots. Determine the appropriate pre- and post-upgrade hook behavior and test it on an Arch Linux system; done means pacman upgrades reliably create both snapshots using btrbk.

Written by the indexing model from the issue text.